NEWPORT, R.I. (AP) -- Seventh-seeded American Jack Sock and third-seeded Australian Lleyton Hewitt advanced to the semifinals at the Hall of Fame Tennis Championships Friday.

The 21-year old Sock, fresh off a doubles title at Wimbledon with Canadian Vasek Pospisil, defeated top-seeded and two-time Newport champion John Isner 6-4, 7-6 (4). The 33-year old Hewitt beat American Steve Johnson 6-4, 6-4.

The two will meet in the semis on Saturday after induction ceremonies honoring the 2014 class into the International Tennis Hall of Fame, which is highlighted by Lindsay Davenport in the recent player category.

The other semifinal is second-seeded Ivo Karlovic of Croatia against Samuel Groth of Australia. Both advanced on Thursday.

Isner won the 2011 and 2012 Hall of Fame titles and had victories in 14 of his previous 15 matches on Newport's grass courts.